HOUSE DUST ALLERGY
WHAT IS HOUSE DUST?
Although there are many components in house dust to which people may become allergic, the most important is the dust mite. This spider-like creature which is found in homes. It cannot be seen with the naked eye. It lives primarily in carpets, mattresses and upholstered furniture and thrives in humid and warm conditions. It feeds on shed scales from human skin! The waste products produced by these mites are highly allergenic. Each mite produces about 20 waste particles each day. These particles continue to cause allergic symptoms even after the mite which has produced them has died. In addition, house dust contains molds, pet dander and cockroach waste which may be allergenic.
WHERE DO DUST MITES LIVE?
The greatest numbers of dust mites can be found in the carpets which provide the best conditions of warmth, humidity and food for their growth. Mites are also present in mattresses, pillows, blankets, upholstered furniture, curtains and similar fabrics. Female mites can lay 25 to 50 eggs, with a new generation produced every three weeks. It is easy to see why carpets may contain such large numbers of living and dead mites.
WHAT CAN BE DONE TO CONTROL DUST MITES?
Scientific studies of dust-allergic patients have shown that taking steps to minimize dust mite exposure in the home can lead to a decrease in allergic symptoms and medication requirements. Emphasis is placed on the bedroom, since people spend one-third or more of their day there. The bedroom is often the room with the greatest number of dust mites. Important dust control measures are noted below:
- The mattress, box spring and pillows should be encased in zippered, dust proof covers. Eliminate “dust catchers” from areas where you spend the most time, e.g., bedroom and living room or den. Use polyester fiberfill pillows. If you do not encase the pillow, change it every 6 months.
- Preferably, floors should be vinyl or wood and covered with washable area rugs only. Carpeting should be avoided. However, if carpeting is present, thorough vacuuming is recommended 1-2 times a week.
- Avoid heavy curtains and venetian blinds if possible. Use window shades instead. If curtains are used they should be laundered periodically.
- Wash bedding in hot water weekly. Wash blankets and comforters in hot water monthly. Avoid wool and down blankets. Remove stuffed toys from the bed.
- House cleaning, epecially “spring cleaning” should be done by someone other than the allergic individual. If that person does the cleaning, he/she should wear a mask while doing so and then leave the house or room for 30 minutes while airborne dust settles. Dust with a damp cloth.
- Air conditioners can control the high heat and humidity which stimulates mite growth. Use a dehumidifier in damp basements. Run a dehumidifier or air conditioner during periods of high humidity, particularly from spring through fall. Change heating/air conditioning filters monthly. “H.E.P.A.” air cleaners can remove airborne dust particles but not the dust mites in bedding or carptets. Covering hot air vents with filters may be beneficial.
- Avoid wall pennants, macrame hangings, unnecessary pillows, books and magazines, stuffed animals and other dust collecting knickknacks. Furniture, if possible, should be wood, leather, plastic or metal as upholstered furniture tends to trap dust allergens and is a site for dust mites to grow.
- Keep all clothing in a closet with the door shut.
- If using a humidifier in the winter, avoid over humidification. Mites grow best at 75-80% relative humidity and cannot live under 50% humidity. Maintain the relative humidity at 40-50% (this can be measured using a humidity gauge).
- If moving, select an apartment or house that is above ground (i.e., no basement living areas), has wooden floors and, preferably, bedrooms on the second floor (i.e., not over concrete which remains damp).